1. Field of the Invention
The present invention is related to a diagnosis assisting apparatus, a diagnosis assisting method, and a storage medium, in which a diagnosis assisting computer program is recorded, that assist diagnosis of cardiac disorders, by displaying analysis results of cardiac functions as bulls eye images.
2. Description of the Related Art
There are known apparatuses that aid image diagnosis by radiologists, that analyze the states and motions of organs of subjects, based on three dimensional data obtained by imaging the subjects, and display the analysis results in a form suited for diagnosis on screens. A function that calculates evaluation indices of cardiac function (amount of myocardial wall activity, variations in myocardial wall thickness, etc.) based on three dimensional data obtained in temporal sequences is known as an analyzing function of cardiac activity. These evaluation indices are calculated for each of a plurality of cross sections, which are set to be perpendicular to an axis that passes through the base of the heart (the upper portion of the heart where blood vessels are connected) to the apex of the heart (the lower portion of the heart shaped as an apex). The calculated evaluation indices are generally displayed three dimensionally to match the shape of the heart. Meanwhile, bulls eye images, in which the evaluation indices for each cross section are arranged along the circumference of concentric circles having different radii, are known as a method for two dimensionally displaying the analysis results (refer to Japanese Unexamined Patent Publication No. 2009-018005, for example).
In addition, a function of displaying images of coronary arteries overlapped on the bulls eye images has also been proposed by Japanese Unexamined Patent Publication Nos. 2005-027999 (corresponding to U.S. Patent Application Publication No. 20050008209) and 2008-253753 (corresponding to European Patent Publication No. 2130490), for example. Abnormalities in cardiac activity (such as myocardial infarction) are often caused by abnormalities (such as occlusions) of the coronary arteries that supply oxygen and nutrients to the myocardial muscles. Therefore, it is desirable to diagnose the states of coronary arteries along with the diagnosis of cardiac function.
The coronary arteries include a right coronary artery and a left coronary artery. The right coronary artery extends downward along the right side surface of the heart. The left coronary artery branches into two arteries, of which one extends downward along the front surface of the heart, and the other extends downward along the left side surface of the heart. The left ventricle of the heart performs the most important cardiac activity of pumping blood throughout the entire body. In the structure described above, the oxygen and nutrients supplied to the myocardial muscled in the vicinity of the left ventricle are mainly transported through the left coronary artery. Accordingly, in the case that abnormalities are recognized in both cardiac activity and the left coronary artery, there is a high probability that there is a causal relationship between the two. In contrast, in the case that abnormalities are recognized in both cardiac activity and the right coronary artery, there is a high probability that there is no causal relationship between the two. Therefore, in diagnoses of cardiac functions, it cannot be immediately concluded that there is a causal relationship between an abnormality in cardiac activity and an abnormality in an coronary artery, even in cases that abnormalities are recognized in both.
The display images proposed by Japanese Unexamined Patent Publication Nos. 2005-027999 (corresponding to U.S. Patent Application Publication No. 20050008209) and 2008-253753 (corresponding to European Patent Publication No. 2130490) are superior in that they enable simultaneous understanding of the evaluation indices of cardiac activity and the states of the coronary arteries. However, they lack data that would enable judgment of the relationship between the two.